1. Field of the Invention
The present invention relates to a plastic sheet having a folded sheet.
2. Description of the Related Art
A related art plastic sheet, for example, a reflector of a sidelight-type backlight unit is configured to be half-blanked or is perforated and half-blanked on a borderline between a surface of a part thereof, which part corresponds to the bottom surface of a light guide plate, and a surface of another part thereof, which part substantially corresponds to a side-surface of the light guide plate, which side-surface does not face a lamp (for instance, see Japanese Utility Model Registration No. 3049260 (page 4, and FIG. 1)) to thereby facilitate the bending of the reflector.
According to the aforementioned related art, a half blanking line or a perforation/half-blanking line is formed in a straight line on the borderline. However, when the reflector is folded on the border line, a restoring force is going to restore the reflector. Therefore, the related art reflector has a problem in that it is difficult for the reflector to maintain a folded state.
Also, the reflector is not only used singly as a plastic sheet but used by being incorporated into the backlight unit. Thus, in a case where the folded state is not maintained, incorporating workability is degraded.
Although the reflector can be fixed by providing an adhesive layer thereon to surely maintain the folded state, the reflector has problems in that deterioration in quality of the backlight is caused due to foreign matters adhering to the adhesive layer, and that the number of component members and the number of steps of a manufacturing process increase, because of the necessity of a step of providing the adhesive layer thereon.